a) Field of the Invention
The present invention relates, in general, to compression-forming machines and, more particularly, to a self-alignment stage for the compression-forming machines which compensates for a relative pose error of a lower mold with respect to an upper mold when a material is compression-formed between the upper mold and the lower mold of the stage and, particularly, self-aligns a wafer on a vacuum chuck, in which the wafer and the vacuum chuck are corresponding to the lower mold, seated on the stage to compensate for a relative pose error with respect to a template corresponding to the upper mold when compression-forming a desired pattern with a material on the wafer, so that an upper surface of the wafer is in parallel surface contact with a lower surface of the template, thus reducing the number of defective products.
b) Description of the Related Art
Generally, compression-forming machines include a lower mold, and an upper mold which is placed above the lower mold and executes vertical directional motions above the lower mold, so that a material seated on the lower mold is compression-formed by the upper mold.
A variety of materials may be compression-formed by the above-mentioned compression-forming machines and, particularly, integrated circuits, which are used in semiconductor manufacturing processes, may be compression-formed on silicon wafers by the compression-forming machines.
Particularly, large scale integrated circuit patterns are formed on the silicon wafers by the compression-forming machines. The large scale integrated circuit patterns force the compression-forming machines to have reduced allowable errors, because the large scale integrated circuit patterns must be precisely formed.
FIGS. 1A and 1B are views showing a conventional compression-forming machine. The above conventional compression-forming machine includes a stage 1, and a vacuum chuck 2 which is placed on the stage 1. The compression-forming machine further includes a template 4 which is an upper mold to vertically move above a lower mold. A wafer 3 is placed on the vacuum chuck 2, in which the vacuum chuck 2 and the wafer 3 are corresponding to the lower mold.
As shown in FIG. 1A, a material M, for example, a photoresist solution is dispensed on the wafer 3 in the compression-forming machine. Thereafter, the material M is compressed by the template 4, then patterns on the template 4 are formed to the material M on the water 3, as shown in FIG. 1B.
During the above-mentioned compression-forming process, an upper surface of the water 3 must be in parallel surface contact with a lower surface of the template 4 to uniformly compress the material M. However, the conventional compression-forming machine is disadvantageous in that an assembling process, in which the elements of the machine are assembled such that the lower surface of the template 4 is in parallel surface contact with the upper surface of the wafer 3, is very difficult, because the template 4 only moves vertically by an actuator.
Furthermore, the conventional compression-forming machine must be equipped with various parts, such as sensors and actuators, so as to allow the upper surface of the wafer 3 to be in parallel surface contact with the lower surface of the template 4. Therefore, the conventional compression-forming machine is problematic in that its structure is complex, and its size and volume increase.